The sedative midazolam is among the drugs used in lethal injections in the state of Oklahoma. (AP Photo/File)

Late Friday afternoon, the Supreme Court announced it would review lethal injection procedures used for many death row inmates across the country after a few of botched executions raised concerns about whether the procedure is unconstitutional.

Those problematic executions include Clayton Lockett, an Oklahoma inmate in April who died of a heart attack 43 minutes after the lethal injection process was started. After the first of a three-drug cocktail was supposed to make him unconscious, Lockett began writhing on the gurney. Months earlier in Ohio, Dennis McGuire struggled and choked for several minutes and took nearly 25 minutes to die from the lethal injection. Arizona inmate Joseph R. Wood took nearly two hours to die, with witnesses saying he gasped and snorted for much of it. Other cases of problematic executions have been reported.

The question before the court now is whether the lethal injection protocol, which has undergone unexpected changes in the past few years, amounts to cruel and unusual punishment.

How lethal injection has changed

Until a few years ago, most lethal injections used a three-drug combination — an anesthetic, a paralytic drug and a drug stopping the heart. The most common anesthetic used was sodium thiopental, but in 2011, its sole manufacturer said it would no longer make it after Italian officials banned export of the drug for capital punishment. So states started using a different anesthetic, pentobarbital — until its manufacturer, a Danish company known as Lundbeck, protested its use in executions.

In turn, states started using new and untested combinations to carry out lethal injections, which is still the main method of executions in the United States. A Germany company said it would stop providing its anesthetic for lethal injections, and a compounding pharmacy last year refused to provide drugs to execute a Missouri inmate.

There's been a high level of secrecy

There's also been secrecy about where and how states are getting these new drugs. As my colleagues reported last April, following Lockett's execution:

In their scramble to carry out death sentences, prison officials from different states have made secret handoffs of lethal-injection drugs. State workers have carried stacks of cash into unregulated compounding pharmacies to purchase chemicals for executions. Some states, like Oklahoma, have relied on unproven drug cocktails, all while saying they must conceal the source of the drugs involved to protect suppliers from legal action and harassment.

“It looks like a street-level drug deal,” said Dean Sanderford, a lawyer for Lockett. “And they’re keeping all the information secret from us. . . . They don’t need to be carrying out any more executions until they come clean, until we know exactly what happened with Clayton’s execution and everything about these drugs, where they’re getting them.”

What's changed in Oklahoma

After a review of Lockett's death, Oklahoma a few months ago announced changes to its lethal injection procedure. The state says it will now use five times as much of the sedative midazolam, which it used for the first time in Lockett's execution last year. The state last week executed its first inmate since Lockett, and there were no apparent signs of distress.

What other states have done

The high-profile botched executions haven't changed much for states around the country. As the Boston Globe reported last month, some states are looking at other ways of executing death row inmates. Oklahoma is apparently looking at becoming the first state to use "forced deprivation of oxygen," while Tennessee may bring back the electric chair and Utah may reinstate the firing squad, according to the Globe.

Support for the death penalty is down

Nationwide support for the death penalty has been declining, but at least 60 percent of people still favor it. After series of botched executions, pollsters expressed doubt those incidents would change public attitudes in a significant way. Still, at least six states have abolished the death penalty since 2007, and 18 states in total ban it.